Technical Field
The present invention relates to an external stereo microphone device attached to; for instance, a mobile electronic device a cellular phone.
Related Art
Multifunctional mobile electronic devices, like cellular phones, tablet terminals, and PDAs, have recently become widespread. There are cases where such a mobile electronic device is used in audio and video recoding applications. However, since many of the mobile electronic devices are not designed solely for audio (video) recording purposes, they are not equipped with microphones suitable for audio recording. Against the backdrop, several stereo microphone devices that can be attached to the mobile electronic devices as appropriate have hitherto been proposed.
However, inmost of the stereo microphone devices attached to the mobile electronic devices, microphones cannot be reoriented over a wide range and hence provide users with poor usability. A cellular phone, in particular, often has cameras on both front and rear sides thereof. When a moving image is recorded by use of the front camera of the cellular phone, it is desired that the microphone be oriented forwardly. In contrast to this, when a moving image is recorded by use of the rear camera, it is desirable that the microphone be oriented backward. Accordingly, the microphone is preferably reoriented through about 180 degrees. However, no external stereo microphone devices fulfilling these requirements have heretofore been available.
Some of the stereo microphone devices built in recorders enable appropriate reorientation of microphones. Recorders that enable reorientation of their microphones are disclosed in; for instance, JP 2009-171355 A and JP 4072679 B and JP 4753978 B. However, all of the devices described in connection with the microphones described in connection with JP 2009-171355 A and JP 4072679 B and JP 4753978 B are specifically designed for audio recording purpose. Since a usage pattern of the recorder (i.e., an orientation of the recorder assumed when it is used) is restricted to some extent, a movable range of the microphone becomes comparatively smaller. Specifically, techniques described in connection with JP 2009-171355 A and JP 4072679 B allow turning of a microphone only over a range of 90 degrees. Moreover, a technique described in connection with JP 4753978 B allows mere adjustment of an intersection angle between directional axes of two microphones over a range from 90 degrees to 120 degrees. Specifically, there have heretofore been available no stereo microphone devices that can change their orientations over a wide range.
Accordingly, the present invention is intended for providing an external stereo microphone device that makes it possible to change orientations of microphones over a wide range.